package com.czk.model.facade;

public class Projector {
    private Projector(){};
    public static final Projector projector=new Projector();
    public static Projector getInstance(){
        return projector;
    }
    public void on(){
        System.out.println("投影仪开");
    }
    public void off(){
        System.out.println("投影仪关");
    }
    public void focus(){
        System.out.println("投影仪聚焦");
    }
}
